Oil catch tank

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hammond
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Oil catch tank

Post by hammond » Fri Nov 12, 2021 10:18 pm

Has anyone ever fitted an oil catch tank to an MGF?

Can it be done? Is it beneficial for the K series?

I know the basic idea of them but couldn't find much with the search function here so was wondering why not.

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Rob Bell
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Re: Oil catch tank

Post by Rob Bell » Mon Nov 15, 2021 10:07 am

That's an interesting question!

I am sure there are those who have fitted a catch can to their MGF, but I bet that has been done in the context of more extensive engine modifications and individual throttle bodies.

The purpose of a catch can is not really for performance benefit as far as I can see, but rather to keep the inlet system clean. On any standard internal combustion engine, the crank case needs venting - and if you vent the crank case, oil vapour will be released to the environment. Old car engines do rather reek of oil (all part of the charm!) but this is not acceptable for modern environmental standards. Since oil burns, manufacturers therefore vent the crank fumes into the inlet system. On the Rover K-series, there's a pipe into the plenum and also to the throttle body. Once ported into the inlet intake, the oil fumes are then drawn into the combustion chambers and burnt.

On a standard road engine, there is no need to consider a catch can. Or at least not on a Rover K-series. It runs cleanly, and oil/soot deposition on the inlet valves simply isn't much of a problem. I suspect this is because the port injection of fuel keeps the inlet tract nice and clean. Direct cylinder injection however may be a different kettle of fish!

On cars with throttle bodies, one needs to consider how to handle these crank case fumes as you have discarded the existing throttle body and plenum. Not sure how this is done on the VHPD derivatives (as found on the MGF Cup cars, but also on Elise and Caterham 7), but on aftermarket solutions, something like this:

Image

Here, one of the vent ports has been blocked, and I think the other either runs to the intake plenum or to a catch can (that can't be seen).

In summary then: yes, it can be done and no, not much benefit unless it is a part of (or mandated by) much wider engine modifications. :)

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Rob Bell
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Re: Oil catch tank

Post by Rob Bell » Mon Nov 15, 2021 10:48 am

Found this picture from a Lotus Elise - catch can is not in the picture, but you can see the blue silicone hose that runs from the cam cover to it:

Image

hammond
Posts: 247
Joined: Fri Oct 14, 2016 5:00 pm
MGF Register Region: Cotswolds
Model of Car: VVC Freestyle

Re: Oil catch tank

Post by hammond » Mon Nov 15, 2021 5:55 pm

Thanks for that in depth reply Rob. So not worth really doing then?
I was thinking of protecting the engine better rather than more power

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Rob Bell
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Re: Oil catch tank

Post by Rob Bell » Mon Nov 15, 2021 6:03 pm

On a standard engine, no, not really worth doing IMO. The standard set up works really very well and the oil condensate in the inlet system while present is really pretty minor and rarely (if ever) causes a problem on the Rover K-series :)

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